The prevalence of obesity is rising at a very alarming rate in the United States. Estimates are that 27% of American adults are now considered obese, and another 52% are overweight. These individuals are at increased risk of premature mortality and the development of many comorbid illnesses. Numerous factors contribute to this epidemic. The medical treatment of obesity is difficult, but can be successful. Drug therapy and obesity surgery can be effective but more research is needed to improve all of the obesity treatments.